def similar_document(first_book, second_book):

    if first_book == '1' or first_book == '2' or first_book == '3' or first_book == '4':
        if second_book == '1' or second_book == '2' or second_book == '3' or second_book == '4':
            percentage = Task4.sentence_similarity(
                first_book, second_book
            )  #trigger the function sentence similarity that will return the score of similarity between two books
            return "The similarity between the two documents is =" + str(
                percentage
            ) + " percent"  #return the score of similarity between two books

    return "Books only from 1 to 4"
def similarity_of_all(string='all'):
    if string.lower() == 'all':
        list_of_sim_matrix = dict(
        )  #creating a dictionary for the similarities score
        count = 1  #intializing count with 1 which having index of book 1
        while (count <= 4):  #iterate through all 4 books
            count_for_second_book = 4  #sceond count has second book indexes
            while (count_for_second_book >=
                   1):  #conditions for books remain in the limit
                percentage_of_each = Task4.sentence_similarity(
                    str(count), str(count_for_second_book)
                )  #triggering task 4 function to get the similarity between two book at a ttime
                list_of_sim_matrix[str(count) + ' and ' +
                                   str(count_for_second_book)] = str(
                                       percentage_of_each)
                count_for_second_book -= 1  #decreement book second

            count += 1  #increement book first
        return json.dumps(list_of_sim_matrix)
    return "Not a required String"